Recipient mailbox full
The recipient’s mail storage is full.
What to do now
- If possible, ask the recipient to check and free mail storage.
- Resend after space is available. For a 4xx reply, check automatic retries on the sending server.
Representative reply
452 4.2.2 Mailbox full
Retry decision
Retry after storage is freed. For 4xx, check automatic queue retries.
Why it happens
The recipient may have exceeded their storage quota.
Typical stage
DELIVERY
- CONNECT
- EHLO
- MAIL FROM
- RCPT TO
- DATA
- DELIVERY
Stages vary by server. Confirm the actual stage from the complete reply and session logs.
What is SMTP Reply Code?Open only the explanations you need
Three-digit server reply: 4xx is transient, 5xx permanent. Read the complete text to investigate the cause.
What is Enhanced Status Code?Open only the explanations you need
An extended status such as 5.1.1. Server wording and usage may vary.
Check directly
- If possible, ask the recipient to check and free mail storage.
- Resend after space is available. For a 4xx reply, check automatic retries on the sending server.
If you operate or diagnose the mail server, the tools below can help with these checks.
Cautions
Observed DSNs do not map one-to-one to causes. The stage shown is typical; confirm it with the full reply and actual logs.
Similar reply wording and observed status codes
mailbox fullmailbox is fullquota exceededover quotainbox is out of storageout of storage spaceexceeded storage
Observed DSNs: 4.2.2, 5.2.2